Orally active factor Xa inhibitor: synthesis and biological activity of masked amidines as prodrugs of novel 1,4-diazepane derivatives

Factor Xa (fXa) is a serine protease, which plays a pivotal role in the coagulation cascade. To improve the oral anticoagulant activity of fXa inhibitors containing a 1,4-diazepane moiety as the P4 part, a prodrug strategy was examined. Among the compounds evaluated in this study, amidoxime prodrugs bearing an ester moiety, such as compounds 21 and 30, showed effective oral anticoagulant activity in mice.     

Dietary amino acid profiles and growth performance in juvenile kuruma prawn Marsupenaeus japonicus

To assess the reference dietary amino acid profiles for juvenile kuruma prawn Marsupenaeus japonicus a feeding trial was conducted using six semi-purified diets containing casein-gelatin and pre-coated supplemental crystalline amino acids (CAA) and a control diet containing intact protein (casein-gelatin). Pre-coated CAA were supplemented to the diets to simulate dietary amino acid profiles to those of the prawn egg protein (PEP), prawn larvae whole body protein (PLP), prawn juvenile whole body protein (PJP), squid meal protein (SMP), short-necked clam protein (SNP) and brown fish meal protein (BFP). The result showed that kuruma prawn juveniles are capable of utilizing the pre-coated CAA and higher growth performances were observed in the groups fed the PJP, SMP and the control diets than those fed the PLP, SNP, BFP and PEP diets. The essential amino acid proportions (A/E ratios) of the whole body of kuruma prawn differ slightly when compared with the other penaeids or freshwater prawn. The results suggest that PJP and SMP would be suitable as a reference dietary amino acid profile for juvenile prawn.     

Measurements of digestibilities of cholesterol and fatty acids using 5α-cholestane as an inert marker in the tilapia, Oreochromis niloticus, and the freshwater prawn, Macrobrachium rosenbergii

An attempt was made to measure the apparent digestibility (AD) of cholesterol and fatty acids using 5aL-cholestane as a marker (cholestane-method) using tilapia. Oreochromis niloticus, and the freshwater prawn, Macrobrachium rosenbergii, as test animals. The results were compared with those obtained by the Cr₂O₃-method. Casein-based test diets containing 0.3% levels of cholestane and chromic oxide as markers were prepared for determination of AD of dietary cholesterol and fatty acids. After 2 weeks of acclimation, the test animals, tilapia (average 3.0 g wet weight) and freshwater prawn (average 0.5 g wet weight) were fed the test diets for 1 week, and faecal samples were collected over 6 subsequent days. Lipids in the diets and faeces were extracted with chloroform-methanol and saponified with 10% KOH in methanol. Gas-liquid chromatography (GLC) on 1.5% OV-17 of the unsaponifiable matters afforded the quantities of 5aL-cholestane and cholesterol, whereas that on 5% Shinchrom E-71 of the saponifiable matters provided the quantities of fatty acids. Chromic oxide was determined by a wet-digestion method. In tilapia, the AD of cholesterol determined by cholestane- and Cr₂O₃-methods were 78.1% and 73.5%, respectively. The AD of individual fatty acids differed with the types of fatty acids, but those of fatty acids determined by the two methods in this study were similar, except for a slightly higher value of several fatty acids such as 16:1 in the cholestane-method than in the Cr₂O₃-method. This indicates that 5α-cholestane as well as Cr₂O₃ can be conventionally used as a marker for determining AD of fatty acids and cholesterol. The cholestane-method is advantageous as it permits parallel analysis of cholesterol (or fatty acids) and 5α-cholestane by GLC using small amounts of faecal sample. The cholestane-method was also useful for analysing digestibilities of cholesterol and total lipids in freshwater prawn. However, slight differences between the cholestane- and Cr₂O₃-methods were observed in the AD of several fatty acids such as 14:0 and 16:1.     

Localization of chemotactic activity and 64 kD protein phosphorylation for human polymorphonuclear leukocytes in N-terminus of the chemotactic protein LUCT/IL-8

A synthetic peptide, AVLPRSAKEL (LU10), the N-terminal amino acid sequence of chemotactic protein (LUCT/IL-8), showed chemotactic activity to polymorphonuclear leukocytes (PMN) with an ED50 of 5 nM for comparable to that of LUCT. Native LUCT and LU10 specifically induced the phosphorylation of 64 kD protein of PMN, and serine residue in the 64 kD protein was major phosphorylated amino acid. Furthermore, native LUCT enhanced the release of myeloperoxidase and beta-glucuronidase from PMN in the presence of cytochalasin B and FMLP, but LU10 did not. These results strongly suggest that the active site for both chemotactic stimulation and 64 kD protein phosphorylation is localized on the sequence of N-terminal 10 amino acids of LUCT.     

Sexual selection in a moth: effect of symmetry on male mating success in the wild

Sexual selection is generally caused by female choice and male–malecompetition. In female choice process, female preference isfavored indirectly and/or directly by sexual selection. In indirectselection, females expressing the preference might gain indirectgenetic benefits. In direct selection, females expressing thepreference might gain direct benefits or avoid male-imposedcosts. The white-tailed zygaenid moth Elcysma westwoodii ismonandrous, and males often gather around a female to mate withher, suggesting a high opportunity for sexual selection on maletraits. We quantified phenotypic selection on male morphologyin this species in the field. The morphological characters analyzedincluded body weight, antenna length, forewing length, hindwing length, hind wing tail length, genital clasper length,and the fluctuating asymmetry (FA) of these bilateral traits.In E. westwoodii, selection favored males with more symmetricgenital claspers, as well as longer and more symmetrical hindwings and antennae. Negative correlations between FA and sizewere also detected in the clasper and the antenna. Our resultssuggest that FAs of male traits, in particular the genital clasper,may have indirect and direct influences on mating success. Duringa copulatory attempt, an E. westwoodii male will try to graspthe female's abdominal tip with his claspers but often failto do so because of the female's reluctance to mate. The femaleabdominal tips are smooth and strongly sclerotized and couldthus be difficult for males to grasp. We hypothesize that moresymmetrical male claspers are more efficient in overcoming femalereluctance.     

Prodrug-based design, synthesis, and biological evaluation of N-benzenesulfonylpiperidine derivatives as novel, orally active factor Xa inhibitors

We describe here our investigation of a new series of orally active fXa inhibitors based on a prodrug strategy. Solid-phase parallel synthesis identified a unique series of fXa inhibitors with a substituted benzenesulfonyl group as a novel S4 binding element. This series resulted in compound 39, which exhibited potent inhibitory activity against fXa (IC50 = 13 nM) and excellent selectivity over thrombin (>7000-fold). The masking of its highly hydrophilic groups led to the creation of related prodrug 28, which demonstrated an anticoagulant effect after oral dosing.     

Design,synthesis and biological activity of YM-60828 derivatives. Part 2: potent and orally-bioavailable factor Xa inhibitors based on benzothiadiazine-4-one template

Compound YM-60828 was previously characterized in our laboratory as a potent, selective and orally-bioavailable Factor Xa (FXa) inhibitor. The L-shape conformation of this compound in the active site of FXa was recognized as an important factor in displaying its FXa inhibitory activity. This led to the exploration of conformationally restricted cyclic scaffolds bearing a similar active conformation. The current study investigated a novel series of benzothiadiazine-4-one based compounds as FXa inhibitors. Structure-activity relationship (SAR) investigations revealed some potent FXa inhibitors that were selected for further in vitro and ex vivo anticoagulant studies. Among them, compound 6j (YM-169920) was proved to be most effective anticoagulant in this series. The synthesis and SAR in addition to docking studies of this class of inhibitors are described.     

Preparation of (4,4-difluoro-1,2,3,4-tetrahydro-5H-1-benzazepin-5-ylidene)acetamide derivatives as novel arginine vasopressin V(2) receptor agonists

The present work describes the discovery of novel series of (4,4-difluoro-1,2,3,4-tetrahydro-5H-1-benzazepine-5-ylidene)acetamide derivatives as arginine vasopressin (AVP) V(2) receptor agonists. By replacing the amide juncture in YM-35278 with a direct ring connection gave compound 10a, which acts as a V(2) receptor agonist. These studies provided the potent, orally active non-peptidic V(2) receptor agonists 10a and 10j.     

Synthesis and biological activity of novel 1,2-disubstituted benzene derivatives as factor Xa inhibitors

Factor Xa (fXa) is a serine protease that plays a pivotal role in the coagulation cascade. High-throughput screening of the Yamanouchi compound library yielded lead compound 1 with the ability to inhibit fXa at micromolar concentrations. To improve its fXa inhibitory activity and its oral anticoagulant activity, the linker between benzamidine and the central benzene ring was modified and a carboxyl group was introduced at the central benzene ring. The resulting compounds 40b (YM-203552), 41a (YM-202054), and 41c (YM-203558) exhibited potent fXa inhibitory activity and oral anticoagulant activity. In particular, YM-203558 exhibited the most potent oral anticoagulant activity, prolonging PT more than 3-fold at 0.5 and 2.0 h. Additionally, these compounds showed a high degree of selectivity for other serine proteases.     

New thiazole derivatives as potent and selective 5-hydroxytriptamine 3 (5-HT3) receptor agonists for the treatment of constipation

The syntheses and biological evaluation of a series of novel indeno[1,2-d]thiazole derivatives are described. Several groups reported 5-HT(3) receptor agonists which were mainly evaluated for their activities on the von Bezold-Jarisch reflex (B-J reflex). We discovered that tetrahydrothiazolopyridine derivative 1b had a contractile effect on the isolated guinea pig colon with weak B-J reflex. Our efforts to find a new type of 5-HT(3) receptor agonists on the isolated guinea pig colon focused on the synthesis of a fused thiazole derivative 1d modified from 1b and reverse-fused thiazole derivatives (7-10). In this series, 10f (YM-31636) showed high affinity and selectivity for the cloned human 5-HT(3) receptor; furthermore, it showed potent and selective 5-HT(3) receptor agonistic activity. YM-31636 was examined for its effects on defecation in animals, thus evaluating the compound as an agent against constipation.